> Documentation index: [Saleor](/llms.txt) · [This section](/developer/llms.txt)
> Source: https://docs.saleor.io/developer/app-store/apps/avatax/development

# Development

To run the AvaTax App locally:

1.  Follow the [_Running Saleor Apps locally_ article](/developer/extending/apps/developing-apps/running-saleor-apps-locally.md).
2.  Go to the app directory.
3.  Copy the `.env.example` file to `.env`.The `.env` should contain the following variables:

info

Taxes is a Next.js application. If you want to learn more about setting environment variables in Next.js, head over to the [documentation](https://nextjs.org/docs/basic-features/environment-variables).

`SECRET_KEY` (_required_)

A randomly generated key that encrypts metadata stored in Saleor. At least eight characters long.

Although it is not required in the development, we recommend to set it. If not set, a random key will be generated on each app start.

`APL` (_optional_)

Name of the chosen implementation of the [Authentication Persistence Layer](https://github.com/saleor/saleor-app-sdk/blob/main/docs/apl.md).

When no value is provided, `FileAPL` is used by default. See `saleor-app.ts` in the app directory to see supported APLs.

`APP_LOG_LEVEL` (_optional_)

Logging level based on which the app will decide on what messages to log.

The possible values are: `trace`, `debug`, `info`, `warn`, `error`, `fatal`, and `silent`. The default value is `silent` which means no logs will be printed.

You can read more about our logger in [its documentation](https://getpino.io/#/docs/api?id=loggerlevel-string-gettersetter).

`ALLOWED_DOMAIN_PATTERN` (_optional_)

A regex pattern that prohibits the app from being installed on a Saleor instance that does not match the pattern. If not set, all installations will be allowed.